Bleaching cane-juice



i UNITED STATES PATENT OFFICE.

AMBROSE G. FELL, OF NEW YORK, N. Y., ASSIGNOR TO WILLIAM H. SMITH,

OF URBANA, ILLINOIS. I

BLEACHING CANE-JUICE, SIRUP, AND OTHER MATERIALS WITH SULPHURIC ACID.8L0.

SPECIFICATION forming part of Letters Patent No. 254,471, dated March 7,1882.

' Application filed October 3, 1881. (No specimens.)

7 To all whom 'lt may concern:

; ment in Bleaching Cane-Juice, Sirups, and oth-' Be it known that I,AMBROSE G. FELL, of NewYork city, in the county and State of New York,have invented a new and useful Improveer Materials with Sulphurous Acid,and in the manufacture of the latter therefor, andfor other purposes,which improvement is fully set forth in the following specification.

V This invention has reference more particularly to the clarifying orbleaching of cane-j nice and other saccharine solutions or sirups bymeans of sulphurous acid, and has for its object to secure a moreeflicient action of the gas, and

2 also to overcome certain difficulties attending themanufacture andappllcation due to its cor- .rrosrve nature.

Various methods have been heretofore de- '-vised for subjecting thesirup to the action of the sulphurous acid and for generating thelatter, but ordinarily the sirup is placed in an open tank six to eightfeet in depth, and the sulphurous-acid gas obtained-say from burningsulphur or compound containing the same-is forced through the liquid bymeans of a pump. The difficulties attending this treatment are that thesulphurous-acid gas passing rapidly through the liquid remains incontact therefice it to say that they are attended in a greater or lessdegree with the disadvantages indicated. Sulphurous acid, therefore, isonly employed to remove a small amount of color from a comparativelylight or thin solution, since to remove the color would require too muchtime and the consumption of too large a quantity of sulphur.

In some cases it is desired to transport the sulphurous acid from theplace of manufacture to where it is to be used. Heretofore the gas froma heavy dark sirup has been forced into vessels by means of pumps, andin order to avoid the corrosion and wear upon the latter it has beennecessary to render the gas anhydrous by removal of the water vapor,thus increasing the labor and expense.

In the present invention the difficulties and disadvantages referred toare overcome or avoided. The cane-juice or sirup is subjected .to theaction of the sulphurous acid in close vessels under high pressure andis intimately mixed and held in contact therewith, so that even withdark-colored sirup a comparatively short time, with small expenditure ofsulphur, is required satisfactorily to remove the coloringmatter. Thepressure in the treating-vessel or in a storage-vessel, when thesulphurous acid is to be kept in supply or transported, is obtainedwithout contact of the gas with a pump, by forcing the air into thechamber in which sulphur is burning, so that air is supplied theretounder pressure, and the gas as it escapes is compressed to the degreerequired for efficient operation upon the sirup or for storage. All theoperations being performed in close vessels, there is no escape of gasto annoy the workmen or to be a source of waste to the manufacturer.

The following description will enable those skilled in the art to whichthe invention relates to make and use the same.

The sulphur or its compound is placed in a close air-tight vesselcapable of sustaining a high pressure. It is preferred to have thisvessel cylindrical in form, and provided with trunnions on which torevolve. The sulphur is ignited in this vessel, and air or oxygen tosupport the combustion is supplied by means of a pipe from anair-compressor leading into the combustion-chamber. By this air oroxygen the combustion of the sulphur and the consequent formation ofsulphurous gas is maintained at any desired pressure. Thecombustionvessel or chamber is provided with an outlet-pipe to conduct the productof combustion (sulphurous-acid gas) to wherever desired for use orstorage. The inlet and outlet are formed in the trunnions.

The reason for preferring a cylindrical rotating vessel in which to burnthe sulphur or its compound is that as the vessel turns on its trunnionsthe melted and burning sulphur adheres to its whole interior surface,thus exposing a larger and thinner area ofsnlphur under combustion thanis practicable in a stationary vessel, and the thinner the area ofsulphur under combustion the less likelihood of volatilizing the sulphurwithout its previous combination with the oxygen, which is necessary tothe formation of sulphurous acid. In a stationary vessel the sulphurmelts by the heat of the combustion, and as that combustion is confinedto the surface of the melted sulphur, the bulk of the sulphur beingtherefore in a melted condition, but not under combustion, is apt tovolatilize in the form of flowers of sulphur. Increasing thecombustion-area by revolving the vessel or chamber in which thecombustion takes place not only lessens the proportion of volatilizedsulphur produced, but also greatly increases the production ofsulphurous acid by exposing to the action of the oxygen of the air alarger area ofsulphur.

After the formation of the sulphurous-acid gas, and previous to itsintroduction into the bleachingchambers or storage -reservoirs, it canbe cooled and purified by any of the various means usually employed forsuch purposes and well understood.

The bleaching-chamber for treating sirups may be an upright cylindricalvessel of about ten by four andone-ha-lf feet,madeofcast-iron andprovided with proper inlets and outlets, a safety-valve, a glass gage,through which the bleaching efl'ectcan be watched as it advances, andalso a stirrer similar in style to a screwpropeller. The stirreriscarried by an upright shaft inclosed in a stuffing-box at the point ofentry into said bleaching-vessel. This vessel is nearly filled withcane-sirup of an inferior grade, darkin color, and'ofany desiredgravity. The stirrer is now put in motion and the supply of sulphurousacid from the combustionchamber is turned on andallowed to flow into thebleacher. The safety-valve is raised, or, if the siru p foams in thebleacher, the valve is set at a few pounds only until the escape ofsulphurous acid therefrom indicates that all the atmospheric air hasbeen displaced and driven out. It is then closed and weighted to fiftypounds, more or less. The sulphurous acid is allowed to accumulate untilthat pressure is reached,when the supply of gas is shut oft, and theagitation continued without the addition of more gas for forty-fiveminutes, or longer, or

until the desired effect is obtained and the operation complete. Thepressure remaining in the bleacher is utilized to force the sirup outofa bottom outlet and pipe into a reception tanlr placed above thebleacher, from whence it can be put through animal-coal, or otherwisetreated to remove the sulphurous acid.

The pressure in the bleaching-chamber is produced direct from the vesselin which the combustion of the sulphur takes place, and that pressure ofacid gas therein contained is continually renewed and maintained bymeans of fresh airsupplied by the compressor, which, bringing intocombustion further amounts of sulphur, insures the continued formationof fresh supplies of sulphurous-acid gas at any pressure within thecapacity of an air compressor or pump, or other device to produce.

As to the style of air-compressor to be employed it is immaterial, asthe gas does not c'ome'in contact therewith, and no consequent corrosionor wear occurs. Any of the wellknown air-pumps will answer, and willlast as long as when employed for any other purpose.

When it is not intended to use the sulphurous gas immediately, or if itis intended for use elsewhere, then the pressure in the combustionchamber is employed to force the sulphurous acid into close and strongstorage-vessels, similar to those employed for storage of carbonic acid,as supplied to the soda-water trade, and in these vessels it can beconveyed to any distance, to be used in any manner and for any purposedesired. The sulphurous acid can be liquefied in these vessels, whichcan be cooled to aid the liquefaction.

From a reservoir of the compressed gas connection may be made with ableaching-chamber, such as described.

In compressing the gas into storage-vessels it is not essential that thegas should be dried but this could be done, if desired, by passing itthrough or over sulphuric acid, chloride of sodium, or any hygroscopicmaterial contained in suitable apparatus, as understood in the arts.

Although the invention, as already described, particularly relates tothe clarification or bleaching of cane-juice or other sirups orsaccharine solutions,it is applicable in part, at least, to otherpurposes. For example, liquids other than cane-juice, or even solidsubstances,

could be placed in the bleaching-chamber and treated with thesulphurous-acid gas under pressure; but with solid materials a stirrerfor agitating them would not ordinarily be required. Analogous means,however, for bringingthe sulphurous acidinto contact with every part ofsaid material could be used.

The pressure of the sulphurous acid in the bleaching or treating chambercan of course be made less or greater, as required, or as deemedexpedient.

The methods before described could be carried out with a stationarycombustion-chamber or with any suitable apparatus, although thatindicated is deemed most advantageous.

The sulphurous acid stored in reservoirs could of course be used for anypurpose to which it might be adapted.

Having now fully described my said invention and the manner of carryingthe sameinto effect, what I claim is-- 1. The method of treating cane-juic'e, sirups, or other materials, solid or liquid, with sulphurous acidby subjecting the same to the action of the sulphurous acid underpressure, substantially as described.

2. The method of bleaching cane-juice, sirups, or other materials,liquidor solid, by sub- IIO jecting the same in aclose vessel to the action ofcompressed sulphurous acid under a high degree of pressure, and usingagitation to bring the acid-gas in contact with all parts of saidcane-juice or other materials, substantially as described.

3. The method of obtaining compressed sulphurous acid for storage or forimmediate use by burning sulphur, or a compound of the same, in a closevessel,forcing compressed air or oxygen into said vessel to supportcombustion, and conveying the products (sulphurous-acid gas) into aclose "essel, wherein the pressure is allowed to accumulate to thedesired degree, substantially as described.

4. The method of producing sulphurous acid by burning sulphur, or acompound thereof, in compressed air or oxygen in a revolving cylindricalvessel or chamber, so as to'expose to the oxidizing action a large andthin area of sulphur, substantially as described. 7

5. The improvement in treating cane-juice or other materials, solid orliquid, with sulphurous acid,consistin g in burning sulphur, or compoundthereof, in compressed air or oxygen, so as to obtain sulphurous acidunder pressure, and subjecting the cane-juice or other material to theaction of the compressed sulphurous In testimony whereof I have signedthis specification in the presence of two subscribing witnesses.

A. G. FELL.

Witnesses:

JOHN McOLURE, J. TALMAN WATERS, Jr.

It is hereby certified that in Letters Patent No. 254,471, granted March7, 1882, upon the application of Ambrose G. Fell, of New York, New York,the title in the grant of said Letters Patent and at the head of theprinted specification attached to and forming a part thereof, waserroneously written and printed improvement in Bleaching Cane Juice,Sirup, and other Materials, with Sulphuric Acid, 850., instead ofBleaching Cane Juice, Sirup, and other Materials, with Sulphnrous Acid,850., that the correct title of said invention is improvement inBleaching Cane Juice, Sirup, and other Materials, with Sulphurous Acid,&c.; that the proper corrections have been made in the files and recordspertaining to the case in the Patent Office, and are hereby made in saidLetters Patent.

Signed, countersigned and sealed this 21st day of March, A. D. 1882.

[SEAL] A. BELL,

. Acting Secretary of the Interior. Uountersigned:

E. M. MARBLE,

Commissioner of Patents.

